Acute Effect of Positive Expiratory Pressure Versus Breath Stacking Technique After Cardiac Surgery

Acute Effect of Positive Expiratory Pressure Versus Breath Stacking Technique After Cardiac Surgery: a Randomized Crossover Trial

This study evaluates the efficacy and safety of a single session of positive expiratory pressure and of breath stacking technique in patients after cardiac surgery. The same patients will receive the two interventions, with an interval of 24 hours, and the acute effect of each will be verifed.

Physiotherapy uses techniques and equipment that reduce postoperative pulmonary complications. The technique called breath stacking consists of an instrumental feature composed of a unidirectional valve coupled to a face mask to promote the accumulation of successive inspiratory volumes. The technique is used to prevent atelectasis and improve gas exchange. Another therapy is called expiratory positive airway pressure (EPAP) that uses positive end expiratory pressure (PEEP) in spontaneously breathing patients, keeping the airway open during expiration. The EPAP system consists of a face mask, a one-way valve and the expiratory resistor, which is responsible for resistance to expiratory flow, which will determine the level of PEEP.

Inclusion Criteria:

Patients with indication for coronary artery bypass grafting and valve replacement, with surgical procedure for median sternotomy.

Exclusion Criteria:

• incapacity to understand the Informed Consent Form.
• cognitive dysfunction that prevents the performance of evaluations or interventions,
• intolerance to the use of EPAP or BS mask
• with chronic obstructive pulmonary disease (COPD)
• cerebrovascular disease
• chronic-degenerative musculoskeletal disease
• chronic infectious disease
• in treatment with steroids, hormones or cancer chemotherapy
• hemodynamic complications (arrhythmia, myocardial infarction during the operation, with blood loss ≥ 20% of the total blood volume, defined by Mannuci, et al., 2007)
• mean arterial pressure <70 mmHg and reduced cardiac output, requiring the use of intra aortic balloon or vasoactive drugs
• tracheal intubation for more than 12 hours after admission to the ICU or reintubated
• individuals unable to maintain airway permeability.